


Derek Hale's Time-Travelling Adventure

by halcyon1993



Series: The Kinky Adventures of a Wolf and His Boy [27]
Category: Teen Wolf (TV)
Genre: Age Difference, Alpha Derek Hale, Anal Fingering, Anal Sex, Bottom Derek Hale, Cock Slut Derek Hale, Come Eating, Come Sharing, Established Relationship, Hairy Derek Hale, Loss of Virginity, M/M, Mates Derek Hale/Stiles Stilinski, Oral Sex, Other, Plot What Plot/Porn Without Plot, Rimming, Self-cest, Size Difference, Spitroasting, Threesome - M/M/M, Time Travel, Time Travel Fix-It, Top Derek Hale
Language: English
Status: Completed
Published: 2018-08-21
Updated: 2018-08-21
Packaged: 2019-06-30 17:30:47
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 6,821
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15756450
Author URL: https://archiveofourown.org/users/halcyon1993/pseuds/halcyon1993
Summary: When Stiles comes across a thirteen-year-old version of Derek, he brings him back to the home he shares with the present-day Derek to keep him safe until he goes back to his own time. What will they do with themselves until then?





	Derek Hale's Time-Travelling Adventure

**Author's Note:**

  * For [Videll](https://archiveofourown.org/users/Videll/gifts).



> As always with this series, don't judge me for the depravity I have written.
> 
> And for those who want me to write bottom!Stiles again, stay tuned for my next PWP. ;)

Stiles is driving home in his Jeep after a long day at work when he sees a young boy walking a little way ahead of him on the side of the road. He eases off the gas as he nears him, lowers the driver's window and is about to ask him if he wants a lift anywhere because he looks too young to be out by himself, but then the boy turns to look at him and Stiles' mind stutters to a halt.

It can't be.

Staring warily at him is a much younger version of Derek Hale, Stiles' mate of several years.

Stiles has of course never seen this version of Derek in person because they met each other when the werewolf was already an adult, but he would know those eyes anywhere. He has also seen many photographs of his mate from when he was a child, after Derek got them out of his family's old vault. They'd made copies and then spent hours compiling them all into photo albums to replace those that were lost in the fire that killed most of the Hales when Derek was sixteen. As illogical as it seems, there is no doubt in Stiles' mind that the boy standing on the side of the road is his mate as a child. He is maybe around 12 or 13 years old, his jaw smooth and his body small and lacking the muscle that Stiles is accustomed to. He's adorable.

"What the hell's wrong with you?" this younger Derek asks him, fed up.

Stiles blinks, still not thinking properly again yet. "What?"

Derek narrows his hazel eyes, and it's been so long since Stiles has seen that suspicious look directed at him that he has to laugh.

"You're weirding me out," Derek says, taking a step backward.

"Hey, it's okay," Stiles hastens to reassure him, realising that Derek is close to bolting. "I'm not gonna hurt you."

"Who are you?"

"My name's Stiles Stilinski."

"I don't know who that is."

Stiles is about to say that his dad is the sheriff, but he stops himself. Would his dad have been the sheriff back when Derek was this age? He can't remember.

"My dad works for the sheriff's department," he settles on saying.

"Wait…Stilinski…" Derek murmurs. "As in the new sheriff?"

That answers that question. "Yeah."

Derek scoffs. "Nice try. Last time I checked, the sheriff's kid was 7, not however old you are. Try again, douchebag."

 _Damn, Derek had a mouth on him when he was younger,_ Stiles thinks amusedly. "Look, this is gonna be hard to explain, but it's the truth okay? And I need you not to freak out."

Derek crosses his skinny arms over his flat chest and tilts his head to the side with a smirk. "Alright, I'll play along. What is it?"

"You're in the future," Stiles replies, figuring it's best if he doesn't dance around it.

The werewolf rolls his eyes. "Very original."

"It's true, Derek."

The mini version of Derek frowns. "How'd you know my name?"

"Because I know you. Or this time's version of you, anyway. You're supposed to be 25."

"Yeah, right."

"I can prove it."

Another scoff. "Sure you can."

Stiles fidgets in his seat and pulls his phone out of the pocket of his blue chinos. He unlocks it and navigates to the Photos app, which is filled with pictures he has taken of the pack over the years. The majority are of Derek, which he started taking after they got their shit together, mated and started living together at the loft last year. He finds a good photo, in which Derek stands in the middle of their kitchen and looks exasperatedly right at the camera, reluctantly allowing Stiles to take his picture for the thousandth time.

"Here, look at this," Stiles entreaties, holding his phone out through the open window.

Derek's curiosity must win out over his disbelief because he steps tentatively toward the Jeep. "What _is_ that thing?"

"It's what a cell phone looks like nowadays."

"It's so thin. Won't it break?"

"Just look at the photo. Please?"

Derek takes another step forward and stares at the phone screen. His mouth drops open. "That's me?"

"Yup. All grown up."

"Really?"

"Really," Stiles confirms. "You should get in so we can figure out what happened to you."

Luckily, the photograph and the phone itself seem to have been enough to convince this mini Derek that something is amiss and that he isn't lying. Mini Derek walks around to the passenger side and gets in but still keeps his distance from Stiles, sitting practically pressed against the door.

"Relax. I won't hurt you, remember?" Stiles reminds him as he starts driving again.

"Where are you taking me?"

"To where you live in this time. You're supposed to be there now, so if you're not then that means you're a de-aged version of this time's Derek. If you are, then that means you're a past version of him and you've somehow ended up in the present. Or the future to you, I guess."

"This is insane."

Stiles chuckles. "Hey, you're a werewolf. Being a supernatural creature with super strength and all that shit isn't insane, but time travel or a spell or whatever caused this is?"

Derek bites into his bottom lip. "When you put it that way…"

"Just hold tight. The loft isn't that far away."

* * *

Five minutes later, Stiles exits the freight elevator in his and Derek's building and leads the way over to the entrance to the loft.

"This is where I live now?" Mini Derek asks him, eyeing the door with disdain. "It's gross."

"It has its own charm."

When they are both inside and he has closed the sliding metal door behind them, Stiles steps further into the loft and scans his eyes over the main part of it. "Derek? You home?" he calls when he doesn't see his mate anywhere.

There comes a sound from the kitchen, and then the Derek that Stiles is used to appears. The werewolf walks across the large space and leans in for a kiss, but before their lips connect he sees the younger version of himself over Stiles' shoulder and freezes.

"Yeah, we have a problem," the human says.

"H-how?" Derek stammers, stepping around Stiles to get a better look at himself.

"I dunno. I just found him on the side of the road on my way here."

"This is bizarre."

"You're telling me. And of course it had to happen when Deaton is out of town and can't help us."

"Oh yeah. How're we gonna figure out how he's here?"

While Stiles and Derek keep talking, Mini Derek circles the older version of himself and is captivated. He'd seen the photograph and knew vaguely what to expect, but seeing the real thing is something else. It's strange seeing himself grown up like this, and he is feeling things he thinks he probably shouldn't. He doesn't have a problem with people not being straight. His older sister is bisexual, and his Uncle Peter had a few short relationships with other men before he found his mate in the woman who is now Mini Derek's Aunt Jasmine. But Mini Derek has never given much thought to his own sexuality. He has just started to notice a few of the girls in his grade but had never looked at another guy with that sort of interest. Until now.

It's probably wrong, but as Mini Derek stares up at his adult self, he feels the stirrings of arousal in his gut. He's just so…manly and pretty at the same time. Stiles is nice to look at too.

But what to do about it?

While Stiles and the older Derek _still_ talk, tossing ideas back and forth, Mini Derek decides not to do anything. Even if he thought it was a good idea, he wouldn't be brave enough.

"I guess that's settled then," Stiles says after another couple minutes.

"What's settled?" Mini Derek asks him, having not been paying attention.

"You'll stay here with us until we can find a way to send you back to your own time. It'll be safer that way."

"Oh." Mini Derek glances at his older self and swallows tightly. Living with these two attractive men is going to be a challenge in self-control. "Okay."

* * *

Over the next few days, it fast becomes apparent to Derek that his younger self is attracted to both him and Stiles.

Whenever he is around, Derek can smell arousal wafting off of him and can feel his eyes on him, and the only time he can't is because they're on Stiles instead. He remembers what it was like to be that age, how his hormones were just beginning to kick into overdrive and nearly everything could turn him on. Plus, while he isn't conceited, he knows what he looks like, and Stiles is the most beautiful man he has ever seen, so it would be only natural for a horny teenage boy to like two attractive people who are for all intents and purposes total strangers to him.

Derek doesn't have that excuse himself.

While his younger self constantly sneaks glances at him and Stiles, Derek sneaks glances right back. There's just something about Mini Derek—the name Stiles has taken to calling him—that does things to Derek that they shouldn't. Mini Derek is just so innocent and small and cute, and Derek finds himself thinking wrong thoughts nearly all the time.

But would it really be so wrong? If anything, it would basically be masturbation. Right?

Right, he tells himself.

Four days after Mini Derek came to stay in the loft, Derek is sitting on the sofa doing some research when Stiles finishes his shower and comes out of the bathroom in just a towel, the bare skin of his torso glistening with water droplets.

"Oh my God…" he hears his younger self gasp.

Derek looks too and smirks because, yes, Stiles' pale skin and lithe muscles are heavenly. "I know," he agrees.

Mini Derek flushes bright scarlet. "I wasn't looking!" he exclaims, the loud volume of his voice drawing Stiles' attention from where he now stands in front of their dresser looking for some clothes.

The human looks to Derek for answers. "What's with him?"

"He was staring at you," Derek responds, smirking, "and he liked what he saw."

Mini Derek covers his face, embarrassed. "Dude!"

Still in just his towel, Stiles leaves the dresser and crouches down in front of Mini Derek. He pulls his hands away from his face. "It's okay."

"It is? You're not mad?"

"Why would I be? It's obvious you'd like me, since the older you damn well does."

Mini Derek turns to his older self. "You do?"

Derek nods. "Yeah. You haven't wondered why Stiles and I live together?"

"I just thought he was staying here while you do research…"

Derek sets his book down on the coffee table and switches seats so that he is right next to his younger self. "Nope. Stiles is my mate. Your mate in the future."

"He is?"

Stiles frowns at Derek. "Should we really be telling him this? What if it changes the past?"

Derek shrugs. "If it does, I don't think it would be a bad thing. Do you?"

Stiles ruminates briefly and concludes that no, it probably wouldn't be. If Mini Derek already has someone on his mind when Kate comes calling…

He grins. "Yup," he tells Mini Derek. "We're mates. See?" He tilts his head to the side to proudly display his mating bite.

Mini Derek lifts his arm and skates his fingers over the ring of raised skin. "Wow."

After a minute, Stiles stands up and goes back over to the dresser, leaving the two Dereks on their own.

"When do we meet him?" Mini Derek enquires.

"Well, right now, we meet him when we're 22 and Stiles is 16. But with us telling you this, it might change things."

"So I might meet him sooner when I go back?"

"I don't know how time travel works in real life, but you might."

"Cool!"

Once his amazement has worn off, Mini Derek looks into his older self's eyes and feels his face go red all over again when dirty thoughts enter his brain. He glances down at his older self's lips.

Derek doesn't miss this and swipes his tongue out to wet them. "Come here," he says.

"Why?"

"You'll see."

Mini Derek climbs into his older self's lap and whimpers when those muscular arms wrap around him and his older self brings their faces close. After a few seconds of staring into each other's identical eyes, Derek closes the remaining distance between them and presses his lips to his younger self's. Mini Derek gasps, giving Derek the perfect opportunity to slide his tongue into his mouth and taste him. He tastes of the Reese's Cups Stiles had bought for him that morning, which was his favourite candy back when he was that age.

"Derek?! What are you doing?!"

Derek breaks the kiss and peers at Stiles over his younger self's shoulder. "What does it look like?"

"But…why?"

"Don't tell me you haven't been thinking the same thing."

Stiles snaps his mouth closed and looks away, confirming Derek's suspicions. "We're not doing anything wrong. He wants this." Derek returns his attention to his younger self. "Don't you?"

Mini Derek nods slowly. "Yeah. You're both so…"

"Hot?" Derek supplies.

"Yeah. Hot."

"See, Stiles? He wants us. And we want him."

Derek wedges his hands beneath his younger self's ass, stands up and carries him over to the bed.

"What are we doing?" Mini Derek asks him as he lays him atop the sheets.

"Whatever you want to do," Derek replies, climbing onto the bed as well. Stiles joins them a second later. He is now fully clothed, but Derek bets he'll be naked again soon enough.

Mini Derek pouts. "I don't know what I want."

"That's okay. We can help you figure it out."

Mini Derek is enraptured when Derek grabs Stiles' chin and slams their mouths together in a filthy kiss. He has seen people kissing like this before—Laura with one of her boyfriends; his Uncle Peter with his Aunt Jasmine—but unlike those other times he isn't grossed out at all. It turns him on, his cock chubbing up in the jeans he'd borrowed which used to belong to Stiles when he was younger.

The two adults seem to get caught up in each other, all but forgetting that there is a third person on the bed. Mini Derek doesn't like that. When Stiles reaches for the hem of his older self's light-grey T-shirt, Mini Derek clears his throat pointedly.

Stiles ends the kiss. "Something wrong?"

"Let me do that."

Mini Derek is glad when Stiles nods and moves away from his older self, allowing him to take his place.

His older self looks down at him with hooded eyes and swollen lips. Mini Derek really takes some time to look at him, at how his features are more defined without any baby fat, his eyebrows are thick and his jaw is framed by neatly trimmed facial hair that he has already felt once against his own smooth face. He wants to feel it again, so he reaches up, fists his small hand in the front of his older self's T-shirt and drags him down into another kiss. This one is more intense than their first, because he isn't too shocked to participate now. He has only kissed one other person before, some girl in his class that he didn't even like that much. But everyone else in his grade seemed to be kissing each other a lot and he hadn't wanted to be left out or made fun of, so he'd done it anyway.

This kiss is way better. Neither he nor the girl had known what they were doing, so it was wet and frankly kind of disgusting, making Mini Derek wonder what the big deal was. Now, as his older self puts his tongue back in his mouth, he gets the appeal. His older self knows what he is doing, and soon Mini Derek is whimpering and hard as a rock in his jeans.

"God, that's nice," he hears Stiles murmur from close by.

When he runs out of air, Mini Derek tears his mouth from his older self's and pulls at his T-shirt. "Off!" he commands, wanting to see what else about him will change in the future.

Derek willingly raises his arms and allows his younger self to take off his T-shirt, baring his torso to the cool air inside the loft. Once it's gone, he turns slightly and lies down so that his head hits the pillows and Mini Derek can look his fill.

The thirteen-year-old gapes, feeling like he might come in his jeans. " _That's_ what I'll grow into?"

"Yup. Hot as fuck, isn't he?" Stiles says, sitting down next to his mate still fully clothed.

"Yeah…"

"I think he wants you to touch him," Stiles tells him. "Isn't that right, Derek?"

The elder Hale nods jerkily.

Mini Derek wants to touch him too, so he moves forward so that he is back in his older self's lap. He can feel something hard beneath him but doesn't let himself get distracted with that just yet.

Before him is the most alluring sight Mini Derek has ever seen. His older self's body is just indescribable, and the knowledge that he will turn into this someday is almost too much to handle. His own body is skinny and weak-looking, which is okay for his age but still has a tendency to make him feel insecure in his own skin. His parents have assured him in the past that it's natural to feel that way at his age and he'll grow into himself as he grows up, and now Mini Derek has irrefutable proof that they were right.

His older self is made of nothing but solid muscle. His chest is broad and huge, his pectoral muscles even bigger than his dad's and his Uncle Peter's. It's covered in dark hairs that are soft when Mini Derek runs his small fingers through them. His own chest is still smooth, his body hair having only just started to really come in, and the contrast is nice to look at. The muscles beneath are hard as rocks, and his older self's nipples are big and pebbled. Mini Derek is struck by the sudden urge to put his mouth on them, so he does.

He sucks on one of them and is proud of himself when Derek moans above him.

Stiles speaks again, stroking a hand down his back. "Yeah, he likes having his nipples played with. Try using your teeth," he suggests.

Mini Derek does as he is told and bites down gently on his older self's nipple, which almost dislodges him from his place in his lap. Derek bucks up beneath him, startled, but he moans again, louder this time, and winds his thick fingers through Mini Derek's short hair to keep him there, which makes it clear that Stiles was right. Mini Derek goes to town, alternating between biting and sucking on his older self's nipples until they're both swollen and raw-looking and the bearded man is writhing beneath him, high-pitched whining sounds pouring from his lips. Mini Derek didn't think he could sound like that after his voice broke, but apparently he can. The sounds go right to his dick.

When he is done, Mini Derek sits up and grinds down onto the hardness he can feel beneath him. He knows it's Derek's cock and is amazed by how big it feels.

"Let's get this off too, shall we?" Stiles says, gabbing Mini Derek's ugly Batman T-shirt, also on loan from Stiles' past wardrobe.

Mini Derek raises his arms and allows himself to be stripped to the same half-naked state as his older self. He feels self-conscious for all of two seconds, until he looks down at his older self's face and sees how lustfully he is looking back up at him. Derek fits his hands around Mini Derek's narrow waist and then strokes them up over his pale, smooth skin. He tweaks his nipples once to give him a taste of his own medicine, and then he moves his hands back down to the waistband of his jeans.

"Wanna take these off?" Derek asks his younger self.

"S-sure," Mini Derek assents.

Derek undoes the button and pulls down the zipper, but he lets his hands fall back down to the bedding when Mini Derek moves away to do the rest himself. The thirteen-year-old doesn't have on any underwear, so once the jeans are off he is left completely naked. Both Derek and Stiles drink in the sight of him with glee, their gazes glued to his cock where it sticks out between his legs. If this were any other situation, Mini Derek would probably be embarrassed enough to cover himself with his hands, but he is still riding the confidence the lust in the older men's eyes gives him. He just kneels there and lets them look.

Stiles is fascinated. While he is a young teenager and as such still has quite a bit of growing to do, Mini Derek is already packing quite the sizeable cock between his legs. Stiles is, of course, well-acquainted with the grown-up Derek's genitals, knows them like the back of his hand, but apparently his mate has always been well-endowed. He doesn't have a ruler handy, but he guesses that Mini Derek's cock is around seven inches long to his older counterpart's eight and a half. The curls at the base are sparser and he is missing some of the girth that Stiles is used to, but he is sure that Mini Derek could still do some major damage with what he has already.

"Can I see yours?" Mini Derek asks his older self, his head slightly bowed.

"Yeah…" Derek responds.

Mini Derek all but pounces, swiftly undoing his older self's jeans and yanking them and his black boxer-briefs impatiently down his legs.

Once the offending garments are off, he is again ensorcelled by the differences between them, how Derek's legs are thick and covered in hairs, unlike his own skinny ones on which his leg hair is just starting to really grow. Derek's balls are large and heavy-looking, hanging low between his muscular thighs with more dark hairs dusting the wrinkled sack, and his cock…Mini Derek is honestly shocked. He had known it would be big from feeling it beneath him and by the size of his own, but seeing it standing proud from the dense pubes at the base is something else.

"Can I touch it?"

Derek's breath hitches. "Y-yeah."

Slowly, Mini Derek raises his hand and wraps it as best he can around his older self's erection. His fingers don't meet his thumb. "It's _massive_!"

"Yup," Stiles agrees, watching this interaction raptly. "And it feels damn good too."

"You've had this inside you?"

"Many times."

"So you're our bottom?"

Stiles shakes his head. "Nah. Both Derek and I are versatile."

"Really?"

"Yeah. Getting fucked feels great if you do it right, so why should Derek miss out on that?"

Mini Derek supposes he understands, even if he hasn't experienced it yet. He'll take Stiles' word for it for now.

"Why don't you try sucking him?" Stiles suggests. "He tastes great as well."

Mini Derek looks back and forth between the human's expectant face and his older self's huge cock. "I guess I can try."

"That's fine. Just suck as much as you can fit in your mouth. I've been blowing him for years and I still can't take it all in my throat. You're gonna be a girthy guy."

With undeniable proof right in front of him that Stiles is again speaking the truth, Mini Derek leans down until his face is mere inches away from his older self's cock. The scent of his sex is all he can smell, his nostrils practically clogged with his older self's musk and the salt of his pre-come. He has to admit that it isn't an unpleasant smell, so he parts his lips and tries to fit the foreskin-covered head of Derek's cock inside his mouth. It's a struggle, but he manages it eventually, his jaw already aching. He can see Derek's hips twitching like he wants to buck up into his mouth and is very glad when the man doesn't actually do so. He would choke.

After a few seconds, Mini Derek gets used to the weight of his older self's cock on his tongue and goes a bit further, taking maybe another inch inside before he has to stop. He pulls off again, licks his lips and swirls the taste of Derek's pre-come around his mouth. Yet another thing Stiles was right about, he muses, finding it delicious.

"Good, huh?" the human grins.

"Uh-huh."

Stiles gets a funny look on his face then, which makes Mini Derek nervous. "I have an idea," he says.

"What is it?" Derek asks his mate, still leaking pre-come.

"I think he should fuck you."

Both Dereks go wide-eyed and stare at each other.

"Really?" Mini Derek squeaks, unsure.

"Really. It would be so hot to watch, and who better to lose your virginity to than your sexy-as-hell future self?"

Derek frowns and looks to the thirteen-year-old. "Is that something you'd want?"

Mini Derek shrugs. "I dunno. I guess it would be cool."

Stiles claps his hands once. "Excellent! Flip over, babe."

Derek rolls his eyes but does as he is told, Mini Derek's hand dropping away from his cock as he turns over onto his front and gets onto his hands and knees.

Mini Derek gapes when he gets his first look at his future self's bare ass. He has never given much thought to other people's asses, but he knows that the one in front of him is amazing; tight globes of muscular flesh with more dark hairs all over, most of them concentrated near the crack. He doesn't do anything for a few moments, just looks, so Stiles grabs Derek's cheeks for him and spreads them apart, letting him see the tight hole hidden between them.

"He tastes great here too," the human says.

Mini Derek doubts it, because how can an asshole taste good? But when Stiles encourages him he brings his mouth close to his future self's hole and hesitantly licks once over it. At first he doesn't really taste anything, but with another lick he notices a slight saltiness on his tongue, as well as something faint and artificial—soap, his mind supplies, which Stiles wouldn't really be able to detect with his human tastebuds. Still, the saltiness is alright, so Mini Derek gets less hesitant with his next few licks, which must meet with his older self's approval because he pushes his ass back onto his tongue.

Stiles smirks. "See? Good, huh?"

"Yeah."

Mini Derek rims his older self for a while, really getting into it. He takes over for Stiles, holding those hairy cheeks apart himself and sticking his face between them. The hairs tickle.

Soon, Mini Derek hears a drawer being opened and, licking his lips, he leaves the muskiness of his older self's ass to investigate. He sees that Stiles now has a tube of something in his hand, which he gives to him.

"Use that to slick up your fingers. Gotta stretch him out for your cock."

Mini Derek complies. He squirts probably more than is necessary on the fingers of his right hand and then, listening to Stiles' next words of guidance, he slides his index finger up to the last knuckle inside of Derek's asshole. It feels so hot and tight around him, gripping him to the point where it nearly hurts, but then Derek's hole relaxes a bit so that he can slide his finger back out. He does this a few times, allowing his older self to get used to the penetration, and then he inserts his middle finger as well.

While he scissors them apart, Mini Derek looks up the long stretch of Derek's tanned back and is surprised when he sees black ink between his shoulder blades. He hadn't noticed the tattoo before because he was too caught up staring at his older self's hairy ass. He recognises the symbol right away as one that is important to his family—a triskelion, three spirals that are connected in the middle. He wonders but doesn't ask when in the future he will get it tattooed onto his skin, and why.

"Doing so good," Stiles tells him. "Isn't he, Der?"

"Yeah," Derek confirms, pushing back onto his younger self's fingers. "Feels good."

"Try curling them a bit." Stiles holds his own fingers up to demonstrate. "Try to find his prostate. That's what _really_ makes anal sex feel so fucking amazing."

Mini Derek nods. "Okay."

With some experimenting, he finds the spot that Stiles was talking about. When he grazes the pads of his fingers over it, his older self gasps and tightens around him, his whole body jerking. Mini Derek does it again, fascinated. He wonders what it feels like and supposes that he'll find out in due time. Maybe one of the men in front of him will get a chance to fuck him before they finally find a way to send him back to his own time. He hopes so.

After he has inserted a third finger, Stiles tells him that that should be enough.

"He likes a bit of a sting with the first push in, don't you, Sourwolf?" the human says, grinning at Derek.

"Sourwolf?" Mini Derek says, confused.

"It's my pet name for you."

"Oh. Weird."

Mini Derek pulls his fingers out and holds still while Stiles squirts some lube onto his big palm and slicks him up. He shudders and fucks into his grip.

"Eager, aren'tcha?" Stiles smirks. "Don't worry, I get it. His ass is _amazing_. Or your ass, I guess."

A few seconds later, Mini Derek puts one hand on the small of his older self's back and uses his other to position the head of his cock at his stretched and slicked-up hole. He pushes inside slowly, tipping his head back when the tip slips past the rim and it clenches tightly around him. He thought he knew somewhat what it would feel like from feeling it around his fingers, but it just doesn't compare. When he has pushed inside all the way to the hilt, Mini Derek curls over his older self's back and rests his forehead against the dip of his spine, just breathing. He is so close to coming already and he has barely begun. _This is gonna be embarrassing._

"Take your time," his older self says, looking back at him over his shoulder.

"O-okay…"

A few minutes pass, during which both Dereks stay exactly where they are and Stiles strokes his hand up and down Mini Derek's back.

When the danger has passed, Mini Derek picks himself back up and pulls halfway out again. He looks down at where they are joined and is entranced by how his older self's hairy little hole seems to grip him like a hungry mouth, like it doesn't want to let him leave the grip of his insides. Mini Derek doesn't want to leave either, so he pushes back in and sets up a decent rhythm. His thrusts are uncoordinated and he has to pause every now and then to readjust his stance into something better. His inexperience is definitely showing, but Derek apparently doesn't mind. The bearded man just moans and murmurs encouragements, telling him how good he feels filling him up.

"In case you haven't already noticed," Stiles whispers close to Mini Derek's ear, "you turn into a _huge_ cockslut."

"I do?"

"Yeah. You'll love feeling a nice big dick pounding your ass. Can't say I blame you. I'm also a slut for your cock."

While Mini Derek continues to fuck his future self, Stiles finally begins taking off his own clothes. Miles of pale, mole-dotted skin are revealed, and while his muscles aren't as big as Derek's, it suits him and Mini Derek is just as attracted to him, especially when he gets a look at the length between Stiles' legs. While Derek is bigger than him here as well, at least in girth, Stiles looks to be just a bit longer, totalling somewhere around nine inches.

Stiles moves around to Derek's other end and smirks at Mini Derek over the length of Derek's body. "This should be fun," he says, tangling his long fingers in his mate's hair. "Wanna be filled at both ends at the same time, Sourwolf?"

Derek looks up at the human and nods, still pushing back to meet his past self's thrusts.

"Open wide then."

When the bearded man does as he is told, Stiles feeds him the first couple inches of his cock, fingers still in his dark hair. Mini Derek can't see it, but he quickly hears the sounds of his older self choking on Stiles' considerable length. Stiles moans as he begins fucking Derek's mouth at the same speed that Mini Derek is fucking his ass, spitroasting him.

The entire situation is too much for Mini Derek, and with a few more thrusts he feels his orgasm approaching again at a rapid pace. He is helpless to stop it, his hips moving of their own accord as they speed up until his balls smack against his older self's. He grips his hips and clenches his eyes shut when it finally hits and he sinks in to the hilt one last time, Derek's asshole clenching up tight around him. He knows that Derek is doing it deliberately, milking the come from him.

After a few seconds, something funny begins happening to the base of his cock, some sort of throbbing that Mini Derek has never felt any of the times he has jerked off over the past year or so. It makes the pleasure even more intense, and somehow he just keeps coming, grinding his hips in small circles to try to get his dick even deeper inside Derek's body. He collapses over Derek's back and wraps his arms around him, whimpering and whining as his vision goes white behind his eyelids and the throbbing at the base of his cock suddenly gets worse. He tries to pull out but can't. Something is stopping him.

"Wha—?" he gasps, managing to angle his face up and peer questioningly up at Stiles. He guesses the human probably knows what's going on.

"You're knotting him, huh?" Stiles says, giving Mini Derek his answer.

"K-knotting?"

"Yup," Stiles confirms, still fucking Derek's face. "I didn't know it developed that young. Cool." He pulls out of Derek's mouth. "How's it feel?"

Mini Derek feels his future self squeeze experimentally around him and whimpers again.

"Fucking amazing. No wonder you always beg me to knot you," Derek says, his voice hoarse from having his throat fucked.

Stiles grins lopsidedly. "Told you. It's pressing right up against your prostate, isn't it? It making you close?"

"Yeah…"

"Why don't you jerk him off?" Stiles suggests, his gaze on Mini Derek now.

The overwhelming pleasure of his orgasm lessening, Mini Derek nods and manages to gather together enough coordination to move one of his hands down from his older self's sternum to between his legs. It's easy to find his cock, what with how big it is. It feels like steel in his hand as he strokes it, the soft skin already slicked up with pre-come. Mini Derek jerks Derek off how he jerks himself off when he is alone in his room late at night, and it doesn't take long for Derek to come too.

Mini Derek's hand is soon covered in thick come, and when his older self's orgasm stops he picks himself up from his back and looks curiously at the mess.

"Gimme a taste of that," Stiles says, hand on his own cock, which is aimed right at Derek's face.

"Sure."

Mini Derek holds out his hand and can't tear his eyes away as Stiles sucks his fingers into his mouth, sucking off the come. Stiles cleans the entirety of his hand, until it's damp with spit instead of semen. "C'mere," he says when he is done.

It's tricky with Derek still trapped between them, but Stiles and Mini Derek contort themselves so that their lips meet over him. Stiles pushes the come he hadn't swallowed into the thirteen-year-old's mouth, and Mini Derek is at first a bit disgusted. The taste and texture is strange and foreign, but when Stiles' tongue leaves his mouth he swirls the viscous fluid around and is surprised by how quickly he gets used to the salty bitterness. It's still not exactly delicious, but the thought of eating his future self's release is hot, so he relishes swallowing it.

While Mini Derek does that, Stiles jerks himself off until he shoots all over Derek's upturned face. It's one of the hottest things Mini Derek has ever seen—which is saying something, given all the hot-as-hell things he has seen over the past hour.

"There," Stiles says when he comes down from his high. "You always look so good with your face painted in come, Sourwolf."

"Shut up, Stiles…"

Derek holds still as the human licks his own releases off of his face and feeds it to both him and his past self, until it's all gone.

With all of them sated, the trio reposition themselves to lie down on their sides. Mini Derek spoons his future self, and Stiles spoons him. It's stupidly comfortable, especially when Stiles pulls the sheets up over all of them. Mini Derek ends up drifting off quickly, worn out and contented by the two mates.

* * *

Two days later, Deaton returns to Beacon Hills and finds the answer immediately, seemingly just sensing the spell that is on Mini Derek. He theorises that some witch had a bit of fun and says that the spell is easy to break. Stiles is sad as he stands with Derek and Mini Derek in the back room of the veterinary clinic, where they say their goodbyes.

"Well, it was fun," he says, hugging the thirteen-year-old tightly.

Mini Derek feels the human slip something into the back pocket of the jeans he is wearing, the same pair he had on the day he appeared in the future. When the embrace ends, he opens his mouth to ask about it but Stiles holds a finger up to his lips and winks at him, his eyes almost pitying, so he leaves it for now. It must be something secret and very important.

A minute later, Deaton performs some sort of spell, there is a flash of light, and Mini Derek is gone.

* * *

When Derek opens his eyes, he finds himself standing outside of his house, still in possession of all the memories of his time in the future. He wonders if that means what happened there will still happen at all before deciding not to worry about it. Thinking too hard about time travelling and paradoxes and all that crap will only give him a headache.

No one in his family seems to know that anything is amiss as he enters the house and greets them all.

"Did you have a good practice?" his mother asks him, looking at him over the back of the living room sofa.

Derek remembers he'd had basketball practice before going to the future. "Yeah, it was good. We got a new guy on our team who's really talented."

"I'm glad. Dinner will be ready in about half an hour."

"Great. I'm gonna go do some homework."

When he is shut up in his bedroom, Derek finally extracts the piece of paper that Stiles had slipped into his back pocket during their hug. He unfolds it and reads the handwritten text. It looks hastily written, as if it was a last-minute decision.

_A woman named Kate will come to town when you're sixteen and try to seduce you. DON'T FALL FOR IT. She's lying. She's a hunter, and she doesn't follow a code. She's really trying to get information out of you to figure out the best way to kill your family. Tell your parents right away when she shows up. Her last name is Argent._

Derek is horrified. Does this mean that, in the future, his family was dead? Stiles' note seems to imply it.

"Not this time," he says, determined.

Whoever this Kate woman is, she is going to get more than she bargained for.

**Author's Note:**

> Thank you to Videll for giving me this prompt. I hope it was everything you hoped it would be. Writing this little piece of filth has inspired me. It won't be for a while as I already have two full-length fics ongoing (check those out if you haven't already), but I've started plans for a proper time travel fix-it fic, in which the pack is all killed and Stiles goes back in time to change things, starting right at the beginning. I'm going to write it anyway, but let me know if you guys think that sounds like something you'd like to read—and if it is, I'd welcome suggestions for things you'd like to see when Stiles visits the past. :)
> 
> Stay tuned for my next PWP, in which fireman!Derek saves Stiles from a burning building. In order to show his gratitude, Stiles brings some homemade brownies to the firehouse, where he stumbles upon Derek in the showers.
> 
> **P.S. Don't forget to subscribe to me to be notified when my future fics go live, which will all be Sterek. And please check out my past fics if you haven't already and are interested.**


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